Tall buildings can make them batty

Bat echolocation is a finely tuned sense. By emitting high-frequency calls and listening for returning echoes, bats can deftly navigate complex surroundings. But a study published Thursday in Science reveals a weak spot in bat echolocation: Smooth, vertical surfaces, like what’s found on tall buildings, can trick a bat into thinking it is flying in open air.

When a bat approaches a smooth, vertical surface from an angle, its echolocating calls mostly reflect away from it. It’s not until a bat gets very close to a flat, vertical surface that some of its calls end up hitting the plate at a 90-degree angle and bouncing right back.

Study author Stefan Greif and his collaborators noted that bats tended to change their echolocation patterns, shortening the time between calls, but that’s often too late. Out of 78 instances they observed of bats coming close to a vertical plate, 53 resulted in crashes.